This invention relates to a method and apparatus for making snow and more particularly to an improved method and apparatus which produces increased volumes of snow at marginal snow making temperatures while achieving a less than one-to-one air to water ratio.
As is well known in the art to which my invention relates, many devices or snow guns have been proposed for making artificial snow. Such devices usually mix compressed air and water internally, then spray the same into the ambient air. The cooling effect from the rapid expansion of the compressed air as well as the cooling effect from the sub-freezing ambient air freezes the water to make snow crystals. These internally mixing devices operate on the principal that a column of compressed air passes through the center of each water exit orifice in the snow gun and pulls or draws the water around a column of air whereby the water is atomized. That is, the water and air flowing through the gun passes around sharp corners and over uneven surfaces and other obstructions to mix the air and water before it is discharged into the ambient atmosphere. This mixing action atomizes the water but reduces the momentum of the mixed air and water as it leaves the gun thus reducing the range and trajectory of the snow plume produced.
Depending on the ambient temperature, the air to water ratio achieved by such internally mixing snow guns was always in excess of three parts air to one part water. This ratio was achieved only at ambient temperatures below 0.degree. F. As the temperature approached 32.degree. F., the air to water ratio would significantly increase. Of the two main components employed, air and water, air is the most costly due to the fact that the cost of air compressors is much greater than the cost of water pumps. The cost of operation of air compressors is also much greater than the cost of operating water pumps.
My U.S. Pat. No. 4,194,689, granted Mar. 25, 1980, discloses a snow gun which discharges through its exit nozzles a centrally disposed column of water surrounded by a sheath of compressed air. This snow gun achieved an air to water ratio of approximately two-to-one while producing increased volumes of snow at higher operating temperatures and with less noise. It thus reduced the cost of making snow by reducing the cost of operation of the air compressors which introduced air into the snow gun.
Some inefficiencies and disadvantages still existed with this gun due to the fact that a lower air to water ratio was desired which in turn would reduce still further the cost of introducing compressed air into the snow gun. Other conventional snow guns with which I am familiar are disclosed in the following U.S. Pat. Nos.: 3,761,020; 3,829,013; 3,897,904 and 4,275,833.